Unable to open. "errors were encountered in this item"

I'm ready to pull my hair out. I borrowed a book from the libby app a week ago, it was fulfilled through ADE and away I went reading my delightful book. 
A week later I have now spent HOURS trying to read another book. I have tried downloading three different books from libby, non of them will open. I keep getting an... "Unable to open.... errors encountered in this item" blurb. 

I have uninstalled, and reinstalled the ADE app many times, I have deleted the device authorizations and restarted again, returned and reborrowed books, deleted and redownloaded book files.....I have tried every solution I can find in the forum posts but all of them are from a few years ago. 

ADE is apparantly the only way I can transfer a library borrowed Ebook onto my kobo....and it's not working even though it was fine a week ago. 

Help please!